It's definitely a stretch for my per-video budget, but I did want to have a 'maxed out' Pi cluster for future testing as well.

A lot of people (here, Reddit, elsewhere) speculate about how good/bad a certain platform or idea is. Since I have the means to actually test how good or bad something is, I try to justify the hardware costs for it.

Similar to testing various graphics cards on Pis, I've probably spent a good $10,000 on those projects over the past few years, but now I have a version of every major GPU from the past 3 generations to test on, not only on Pi, but other Arm platforms like Ampere and Snapdragon.

Which is fun, but also educational; I've learned a lot about inference, GPU memory access, cache coherency, the PCIe bus...

So a lot of intangibles, many of which never make it directly into a blog post or video. (Similar story with my time experiments).